The invention relates to a suturing instrument for use in surgical operation, especially for suturing up a wound or cut out skin with a series of lock stitches composed of a needle thread and a shuttle thread.
In the past, the surgical suturing operation has been made by means of a curved needle having a needle eye provided at the base thereof and a separate needle holder. After inserting a suture-thread through the needle eye, the operator clumps the base of the needle by the needle holder and pierces the needle into the flesh at one side of a wound or a cut out skin and projects the needle to the skin at the opposite side of the wound. Then the operator clamps the projected end of the needle with a holder and pulls the needle out of the skin to pass the suture-thread from one side to the opposite side of the wound. The suture-thread is then tied up per stitch. Thus the wound or cut out skin has been sutured up with a number of tied seams. Such a suturing operation is, however, time consuming, and is a physical burden to the patient.
For the purpose of improving the suturing operation, a suturing instrument has been proposed by the prior art (see Pat. No. 2,327,353) as shown in FIGS. 1 and 2, in which a curved needle 1 is removably attached to a needle bar 2. The needle has a needle eye 1a provided near the pointed end thereof and a groove 1b provided on the outer side of the needle shank therealong for guiding a needle thread 3 therein. The needle thread 3 is locked with a shuttle thread 5 carried by a shuttle 4 which is reciprocatingly moved with respect to the needle 1 to suture up the wound or cut out skin with lock stitches.
Namely, according to the suturing instrument, the needle thread 3 is drawn out of a bobbin (not shown) mounted on a support 6 and is passed through an eye 7a of a thread guide 7 and is then guided in the guide groove 1b of the needle 1 and is then passed through the needle eye 1a. When the curved needle 1 is pierced through the parts 8, 9 of skin, a crescent-shaped thread loop 3L is formed by a part 3a of thread extended between the needle eye 1a and the skin 9a and a part 3b of thread guided in the needle groove 1b. Then the shuttle 4 with the shuttle thread 5 is moved into the thread loop 3L to lock the part 3a of the thread loop 3L with the shuttle thread 5. Then the curved needle 1 is moved back and pulled out of the skin 8, 9 to tighten the two threads 3, 5, thereby to form a lock stitch. With repetition of such an operation, a series of lock stitches is formed to suture up the wound. As to the suturing instrument, the shuttle 4 has to be positioned on the side of the support 6 spaced from the needle so as not to be in the way when the needle is pierced into the skin to be sutured up. The shuttle 4 is required to reciprocate in a linear or a curved path between the needle 1 and the inoperative position at the side of the support 6 so as to lock the needle thread loop 3a with the shuttle thread 5.
According to this suturing instrument, the shuttle 4 is movably supported on the support 6 with the forward end thereof directed to the curved needle 1, so that the shuttle with the shuttle thread 5 may be passed into the needle thread loop 3L in the advancing movement toward the needle 1 for locking the thread loop 3a with the shuttle thread 5. The thread locking is completed while the shuttle 4 is returned to the inoperative position at the side of the support 6.
More precise explanation of this thread locking operation may be made in reference to the additional FIGS. 3-5.
The generally streamlined shuttle 4 is held within a shuttle holder 11 which is mounted on the support 6 and is reciprocatingly movable with respect to the curved needle 1 which is removably attached to the free end of the needle bar 2, the opposite end of which being secured to the support 6 as shown. Within the shuttle holder 11, the shuttle 4 is at the bottom thereof supported by a support plate 13. The forward end of the shuttle 4 is projected from the shuttle holder 11 and is pressed by the forked ends 16a of a pawl 16 having a shank turnably connected at one end thereof to the side walls 12 of the holder 11 by a pivot screw 14 and is biased in the counterclockwise direction in FIG. 4 by a spring 15. The shuttle 4 has a projection 4a with an eyelet 4b provided at the forward bottom thereof for connecting one end of the shuttle thread 5 thereto. After the loop 3L is formed, the shuttle holder 11 is moved in the direction as shown by an arrow E in FIG. 3, and the forward end of the shuttle 4 is passed below the straight part 3a of the needle thread loop 3L. As the holder 11 is advanced, the needle thread 3a is guided along the upper part of the shuttle 4 between the shuttle and the detaining ends 16a of the pawl 16 against the action of the spring 15. The needle thread 3a is further passed over the shuttle 4 and comes between the rear end of the shuttle 4 and the inner wall 12a of the holder 11. Then, as the holder 11 is moved back, the needle thread 13a is passed down between the rear end of the shuttle 4 and the inner wall 12a of the holder 11. As the holder 11 is further moved back, the needle thread 13a is passed towards the forward end of the shuttle guided between the bottom of the shuttle 4 and the support plate 13. Thus, the needle thread 3a is locked with the shuttle thread 5 as shown in FIG. 5 after the shuttle holder 11 is moved back to the inoperative position. According to the suturing instrument, the shuttle 4 with the pointed forward end is liable to hurt a part of the wound or the to be sutured as the shuttle 4 comes to a position shown by the two-dotted line in FIG. 5.